1. Field of the Invention:
This invention relates to flake like metal chips or particles for use in strengthening the surface zone of a laid concrete floor by embedding such chips and to a method of and an apparatus for producing the same. More particularly, this invention relates to a method of making such chips of comparatively small size (for instance, 3.0 mm or less) by a simplified manner and by using an apparatus of simplified construction also in mass production.
2. Prior Art:
Since a laid concrete floor itself is generally soft and low in hardness, it is liable to be worn due to abrasion not only by articles of high hardness but also by such soft articles as those made of wood.
By taking these situations into consideration, the laying of concrete in modern construction adopts a way of improving wear resistant property and of preventing cracks from occurring on the surface of the concrete by embedding or scattering metal particles in the surface layer of the concrete floor.
Such metal particles as have heretofore been used for reinforcing concrete floors were supplied in the form of finely crushed machine tools chips or as cut chips obtained in making nails. Due to these facts, there have been many problems of not only a poor production efficiency but also poor uniformity in size and shape, thereby rendered uniform embedding of these particles in concrete floor very difficult.
As a prior art that the inventor of this invention recognises, there are such a method of and an apparatus for forming flake particles as disclosed by Japanese Laid-Open Patent Publication Sho-54(1979)-40262. The method of forming the flake particles comprises the steps of:
(a) rotating a heat-extracting drum which is provided around its peripheral rim with a plurality of tapered serrations;
(b) advancing the serrations formed on the drum onto the surface of molten material to form a number of independent flake particles, then letting said particles partially solidify on said serrations by extracting heat from said serrations;
(c) releasing the particles from the serrations; and
(d) cooling the thus released particles in a surrounding air.
However, the particles obtained by the above method are formed as mere flat flakes, so they are not relevant to the main object of the present invention.